Snap-acting flasher switch

ABSTRACT

The snap-acting flasher switch comprising an insulated base, a supporting terminal and a high-resistance wire terminal carried by said base, an elongated rectangular resilient vane secured at the top to the supporting terminal. Said vane is provided with a combined circular and triangular opening and prestressed by crimping the edge adjacent to the base of the triangular opening. A thermally expansible and contractable ribbon is arranged in spaced relation along the inner face of the vane and secured under tension at its ends to the edges of the vane so as to stress the vane against the force of the prestressing thereof to hold the vane inwardly. The vane is provided with a movable contact cooperative with the stationary contact attached to the supporting terminal. Around the ribbon, a high-resistance wire is wrapped with its end electrically connected to said ribbon while the other end being connected to the terminal.

United States Patent [72] Inventors Masamitsu Nakano Yokohama; KazumiShinozuka, ltakomachi, .Namekatagun, both of Japan [21 1 Appl. No.869,068 [22] Filed Oct. 24, 1969 [45] Patented Sept. 28, 1971 {73]Assignec Nagatoshi Suzuki Otaku, Tokyo Japan [32] Priority Nov. 30, 1968[33] Japan [31 43/103908 [54] SNAP-ACTING FLASHER SWITCH 1 Claim, 10Drawing Figs.

[52] US. Cl 337/136 [51] Int. Cl ..H0lh 3 7/02, HOlh 37/46 [50] Field ofSearch 337/135, 136,138, 140,391

[56] References Cited UNITED STATES PATENTS 3,349,205 10/1967 Taylor337/138 X Primary Examiner-Harold Broome Assistant Examiner-Dewitt M.Morgan AttorneyJoseph J. .Iuhass ABSTRACT: The snap-acting flasherswitch comprising an insulated base, a supporting terminal and ahigh-resistance wire terminal carried by said base, an elongatedrectangular resilient vane secured at the top to the supportingterminal. Said vane is provided with a combined circular and triangularopening and prestressed by crimping the edge adjacent to the base of thetriangular opening. A thermally expansible and contractable ribbon isarranged in spaced relation along the inner face of the vane and securedunder tension at its ends to the edges of the vane so as to stress thevane against the force of the prestressing thereof to hold the vaneinwardly. The vane is provided with a movable contact cooperative withthe stationary contact attached to the supporting terminal. Around theribbon, a high-resistance wire is wrapped with its end electricallyconnected to said ribbon while the other end being connected to theterminal.

PATENIEUSEP28|9Y| v 3.609519 I saw 2 0F 2 I INVENTOR maocdmw WATTORNEYSNAP-ACTING FLASIIER SWITCH The principal object of this invention is toprovide an improved snap-acting flasher switch, which is particularlyadaptable for use in directional turn signal systems for automotivevehicles, and which opens and closes the turn signal electric circuitsin regular and uniform fashion to provide substantially equal on and offperiods; which is sturdy in construction and reliable in operation, andwhich is inexpensive to manufacture andinstall.

Further objects of this invention reside in the detail of constructionof the snap acting flasher switch of this invention and in thecooperative relationships between the component parts, including theconstruction and operation of the snap acting vane and its associatedheater ribbon and contracts and the manner of mounting the same to forma sturdy and reliable flasher switch unit.

Other objects and advantages of this invention will become apparent uponreference to the accompanying specification, claims and drawings inwhich: i

FIG. 1 is a plan view of thesnap acting vane before deformation, 7

FIG. 2 shows the vane in the first deformed state,

'FIG. 3 shows the vane in the second deformed state,

FIG. 4 is a perspective view of one end of the thermally expansible andcontractable heater ribbon,

FIG. 5 is a perspective view of the other end of the heater ribbonattached to the vane,

FIGS. 6A and 6B show the twosteps involved for securing the highresistance wire to its tenninal,

FIG. 7 is a front view of the snap-acting flasher switch of thisinvention,

FIG. 8 is its wiring diagram, and

FIG. 9 shows the snap-acting vane with relative dimensions.

The snap-acting flasher switch of this invention includes an insulatingbase 12 formed of suitable insulating material such as Bakelite or thelike. The base 12 carries a supporting terminal l3 and the otherterminal 8 for high-resistance wire 7. The snap-acting vane lincorporated in the flasher is made of relatively thin electricallyconductive spring metal such as beryllium copper or spring steel and isof an elongated rectangular form, with consideration being given to itsspring factor, stiffness, temperature coefficient, and the like, inaccordance with the desired rate of operation of the snap action.

To provide an initial set to the vane 1 and to give the same some depthso that it will resemble a beam in its action, the vane is deformed.This deformation is effected by providing a circular opening A and alaterally extending triangular opening B connected therewith in the faceof the vane and by crimping the edge C of the vane adjacent to the baseof said triangular opening B. C is the crimped portion. This crimp Cshortens the side edge of the vane so as to cause the other side edgethereof to have a greater effective length larger than the crimped sideas shown in FIG. 2 edge.

When the vane-bending forces are applied by means of a thermallyexpansible and contractable ribbon 5 stretched across the vane along theline which is somewhat oblique to the upper edge of the vane and whenthe value of these forces equals or overbalances the inherent tendencyof the vane to stay in its normal condition, the vane snaps into a newbend or a second deformed position forming another arc.

When the stretching force is decreased to a point where it isoverbalanced by a kinetic energy stored in the vane 1 due to suchdistorting force, the vane snaps back to the previous position.

In order to arrange the ribbon 5 in spaced relation along the inner faceof the vane 1, one end of said ribbon is folded and spot welded to oneside edge of the vane as shown in FIG. 5 while the other end thereof isspot welded to a tab 6 attached to the other side edge of the vane.

As the space between the ribbon 5 and vane I may be kept sufficientlywide, the vane can .move freely and further, by manipulating the tab 6with a suitable tool, the tension in the ribbon 5 may be adjusted atwill.

The vane l is preferably provided with projections 3 and 4 at the topand bottom side edges of the vane respectively. The projection 3 is forspot welding the vane to the supporting terminal l3 and the projection 4is for attaching a movable contact [4. A stationary contact 15 isattached to the supporting terminal 13 (FIG. 5).

The ribbon 5 is heated by a high-resistance insulated wire'7 wrappedaround the ribbon and having one end electrically connected thereto.After the other end of said wire is wrapped around the terminal 8 (FIG.6(l) the terminal is bent double as shown in FIG. 6 (II) so as to effectgood contact between said wire and terminal without soldering orwelding. The wire 7 being very flne, this is the best way of connectingit to the terminal.

The operation of the device will be understood from FIG. 8 and thefollowing description. The unit is inserted into an appropriatereceptacle so that the terminal 13 is electrically con nected to oneside of a grounded battery 9, terminal 8 is connected to parallelgrounded signal lamps 11 through a switch 10. When the switch 10 isclosed, the current flows as follows;

Battery 9 wire 7 switch 10 lamps 11. Due to the ie-- sistance of wire 7,the current flow is insufficient to light lamps ll. Wire 7 heats up, theribbon Sexpands and vane l snaps to engage its contact 14 with thecontact 15. Engagement of contacts 14 and 15 completes a second circuitshunting wire 7. Current flows as follows;

Battery 9 vane l lamps 11.

The current flow is now sufficient to light lamps ll. Ribbon 5 now coolsand contacts to snap vane 1 back to its stressdeformed conditiondisengaging contacts 14 and 15 to extinguish lamps l l, and the cyclerepeats.

For reference, the dimensions of the typical snap acting vane accordingto this invention (FIG. 9) are:

contacts 14 and 15 switch 10 What I claim is:

l. Snap-acting flasher switch comprising, an insulated base, avane-supporting terminal carried by the base, a high-resistance wireterminal carried by the base, an elongated rectangular resilient vanehaving a combined circular and triangular opening, said vane beingprestressed by the provision of crimps in the edge of the vane adjacentthe base of the triangular opening and provided with projections at thecenters of the upper and lower edges of the vane respectively, the upperprojection being secured to the upper end of the supporting terminal andthe lower projection being provided with a movable contact, a thermallyexpansible and contractable ribbon arranged in spaced relation along thevane and stretched obliquely so as to stress the vane against the forceof the prestressing thereof to hold the vane inwardly, one end of saidribbon being folded over and secured to one side of the vane and theother end being welded to a tab attached to the opposite side of thevane, a stationary contact attached to said vane supporting terminal,and high resistance wire, one end of which being wrapped around theribbon and the other end being wrapped around said high resistance wireterminal and secured thereto by folding said terminal.

1. Snap-acting flasher switch comprising, an insulated base, avane-supporting terminal carried by the base, a high-resistance wireterminal carried by the base, an elongated rectangular resilient vanehaving a combined circular and triangular opening, said vane beingprestressed by the provision of crimps in the edge of the vane adjacentthe base of the triangular opening and provided with projections at thecenters of the upper and lower edges of the vane respectively, the upperprojection being secured to the upper end of the supporting terminal andthe lower projection being provided with a movable contact, a thermallyexpansible and contractable ribbon arranged in spaced relation along thevane and stretched obliquely so as to stress the vane against the forceof the prestressing thereof to hold the vane inwardly, one end of saidribbon being folded over and secured to one side of the vane and theother end being welded to a tab attached to the opposite side of thevane, a stationary contact attached to said vane supporting terminal,and high resistance wire, one end of which being wrapped around theribbon and the other end being wrapped around said high resistance wireterminal and secured thereto by folding said terminal.